While diving in North Sulawesi, we came across a fantastic small colony of Oxypora lacera, the Watermelon Chalice. While this color morph is quite common in Australia, it’s quite rare in Indonesia.
The perfect red colony color, with a green growth edge, gave it the Watermelon name. But the gold polyp mouth is really a great additional feature.
Oxypora lacera is a very common coral. They produce thin foliate, unifacial colonies (thin plates with polyps on one side only). Irregular corallites have poorly defined walls and coarsely ornamented and toothed costae running between polyps. Corallites are generally smaller than the ones of Echinophyllia and Mycedium, and more ornamented, with thicker tissues than those ones of Echinopora.
This particular colony was actually pretty shallow, just over 5 m (15ft) deep, on the side of a shallow bommie, in a very turbid, protected inshore reef, full of other LPS corals. Being on the side of the bommie only exposes the corals a few hours a day to sunlight.
Every time we dive into this particular spot, we never get better visibility than 5 m (25 ft). The water is very turbid there, and a river flows into the end of the protected Bay, bringing a large amount of nutrients. The cup shape with a larger corallite at the bottom of it is probably very helpful for feeding in this particular environment.
The few rocks not covered with LPS corals are covered with algae, but so far the LPS manage to dominate algae. This particular reef is filled with Fimbriaphyllia ancora, F. paradivisa, and F. divisa colonies. And also huge fields of Plerogyra simplex, Plerogyra sinuosa, and Plerogyra sp, in all possible colorations.
All the photos were taken using 6000K flash. Probably that under blue Led, this color would just be mind-blowing!